Tetrahedron, asymmetry最新文献_第3页

Highly enantioselective asymmetric reactions involving zinc ions promoted by chiral aziridine alcohols 手性氮啶醇促进锌离子的高度对映选择性不对称反应

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/J.TETASY.2017.10.007

Szymon Jarzyński, G. Utecht, S. Leśniak, Michał Rachwalski

引用次数: 10

Four new norlignan glycoside isomers from the twigs of Cephalotaxus oliveri Mast. 头豆杉枝条中四个新的去木脂素苷异构体。

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.017

Fan-Cheng Meng , Hui Liu , Xiao-Jun Huang , Yu Chang , Dai Ren , Li-Gen Lin , Qing-Qian Zeng , Qing-Wen Zhang

引用次数: 6

Synthesis and stereochemical assignment of geraniol- and nerol-derived Cygerol enantiomers 香叶醇和橙醇基香叶醇对映体的合成及立体化学配位

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.024

Anna A. Sukhanova, Ilya A. Puchkin, Andrei A. Vasil'ev, Sergei G. Zlotin

引用次数: 1

Asymmetric syntheses of the N-terminal α-hydroxy-β-amino acid components of microginins 612, 646 and 680 微蛋白612、646和680 n端α-羟基-β-氨基酸成分的不对称合成

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.09.022

Stephen G. Davies, Ai M. Fletcher, Abigail R. Hanby, Paul M. Roberts, James E. Thomson

{"title":"Asymmetric syntheses of the N-terminal α-hydroxy-β-amino acid components of microginins 612, 646 and 680","authors":"Stephen G. Davies, Ai M. Fletcher, Abigail R. Hanby, Paul M. Roberts, James E. Thomson","doi":"10.1016/j.tetasy.2017.09.022","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.09.022","url":null,"abstract":"<div>The asymmetric syntheses of the N-terminal α-hydroxy-β-amino acid components of microginins 612, 646 and 680 are reported. Conjugate addition of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide to the requisite (E)-α,β-unsaturated ester followed by in situ enolate oxidation with (−)-(camphorsulfonyl)oxaziridne (CSO) gave the corresponding anti-α-hydroxy-β-amino esters. Sequential Swern oxidation followed by diastereoselective reduction gave the corresponding syn-α-hydroxy-β-amino esters. Subsequent N-debenzylation (i.e., hydrogenolysis for microginin 612, and NaBrO3-mediated oxidative N-debenzylation for microginins 646 and 680) followed by acid catalysed ester hydrolysis gave the corresponding syn-α-hydroxy-β-amino acids, the N-terminal components of microginins 612, 646 and 680, in good yield. An analogous strategy for elaboration of the enantiopure anti-α-hydroxy-β-amino esters facilitated the asymmetric synthesis of the corresponding C(2)-epimeric α-hydroxy-β-amino acids.</div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91631057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Highly enantioselective asymmetric reactions involving zinc ions promoted by chiral aziridine alcohols 手性氮啶醇促进锌离子的高度对映选择性不对称反应

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.007

Szymon Jarzyński, Greta Utecht, Stanisław Leśniak, Michał Rachwalski

引用次数: 10

Efficient lipase-catalysed route for the kinetic resolution of salsolidine and its ß-carboline analogue 高效脂肪酶催化的salsolidine及其ß-carboline类似物动力学分解途径

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.019

Barbara Kovács, Rita Megyesi, Enikő Forró, Ferenc Fülöp

{"title":"Efficient lipase-catalysed route for the kinetic resolution of salsolidine and its ß-carboline analogue","authors":"Barbara Kovács, Rita Megyesi, Enikő Forró, Ferenc Fülöp","doi":"10.1016/j.tetasy.2017.10.019","DOIUrl":"10.1016/j.tetasy.2017.10.019","url":null,"abstract":"<div>Racemic 1-methyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 1 and 1-methyl-1,2,3,4-tetrahydro-ß-carboline 3 were resolved through lipase-catalysed asymmetric acylation on the secondary amino group. High enantioselectivities (E >200) were observed when the acylation of racemic 1 was performed with phenyl allyl carbonate in the presence of Candida rugosa lipase in toluene at 40 °C or with Candida antarctica lipase B in tert-butyl methyl ether at 50 °C. Excellent enantioselectivity (E >200) characterised the CAL-B-catalysed acylation of racemic 3 with phenyl allyl carbonate in the presence of triethylamine in tert-butyl methyl ether at 50 °C. The product (R)-carbamates (ee >97%) were hydrolysed into the corresponding (R)-enantiomers of the free amines 1 and 3 (ee = 99%) with the use of Pd2(dba)3·CHCl3 catalyst.</div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86639587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

A convergent approach towards the synthesis of the 2-alkyl-substituted tetrahydroquinoline alkaloid (−)-cuspareine 合成2-烷基取代四氢喹啉生物碱(−)库柏碱的收敛方法

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/J.TETASY.2017.10.023

M. Madhubabu, R. Shankar, T. Krishna, Y. Kumar, Y. Chiranjeevi, C. Muralikrishna, H. Mohan, Satish S. More, M. Rao, R. Akula

引用次数: 2

Asymmetric syntheses of the N-terminal α-hydroxy-β-amino acid components of microginins 612, 646 and 680 微蛋白612、646和680 n端α-羟基-β-氨基酸成分的不对称合成

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/J.TETASY.2017.09.022

S. Davies, Ai M. Fletcher, Abigail R. Hanby, P. M. Roberts, J. Thomson

引用次数: 3

Synthesis of enantiomerically pure 2-(N-aryl, N-alkyl-aminomethyl)aziridines: a new class of ligands for highly enantioselective asymmetric synthesis 对映纯2-(n -芳基，n -烷基-氨基甲基)叠氮嘧啶的合成:一类用于高对映选择性不对称合成的新配体

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.018

Szymon Jarzyński, Stanisław Leśniak, Michał Rachwalski

引用次数: 7

Lipase-catalyzed kinetic resolution approach toward enantiomerically enriched 1-(β-hydroxypropyl)indoles 脂肪酶催化对映体富集1-(β-羟丙基)吲哚的动力学分解方法

Tetrahedron, asymmetry Pub Date : 2017-12-15 DOI: 10.1016/j.tetasy.2017.10.010

Paweł Borowiecki , Iwona Justyniak , Zbigniew Ochal

{"title":"Lipase-catalyzed kinetic resolution approach toward enantiomerically enriched 1-(β-hydroxypropyl)indoles","authors":"Paweł Borowiecki , Iwona Justyniak , Zbigniew Ochal","doi":"10.1016/j.tetasy.2017.10.010","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.10.010","url":null,"abstract":"<div>In a route towards enantiomerically enriched 1-(β-hydroxypropyl)indoles, which are potentially useful building blocks for high value-added chemicals synthesis, a kinetic resolution approach by means of lipase-catalyzed enantioselective acylation as well as hydrolysis/methanolysis has been elaborated for the first time. The enzymatic resolution of chiral N-substituted indole-based sec-alcohols was successfully accomplished, yielding both enantiomeric forms of the employed derivatives with up to >99% enantiomeric purity via an enantioselective transesterification under mild reaction conditions. The most selective resolutions were obtained using fungal (CAL-B and TLL) and bacterial (PFL and BCL) lipases and vinyl acetate as the acyl group donor. The synthetic protocol described herein is very simple, user-friendly and efficient, thus paving the way for future access towards more complex compounds of this type. The absolute configurations of novel enantiomeric derivatives, and thus stereoselectivity of the described enzymatic reactions were confirmed by application of CDA-based NMR methodology and single-crystal X-ray diffraction analysis.</div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91631160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15